53 Pa. Stat. § 881.204
In computing the length of service of a contributor for retirement purposes, full credit shall be given to each original member for each year of service rendered to the municipality prior to the time the municipality joined the system, whether or not such service was continuous.
As soon as practicable, the board shall issue to each original member a certificate certifying the aggregate length of service rendered to the municipality prior to the time it joined the system. Such certificate shall be final and conclusive as to his prior service unless thereafter modified by the board, upon application of the member.
The time during which a member was absent from service without pay shall not be counted in computing the service of a contributor in his certificate, or upon retirement, unless specifically allowed by the municipality, with the approval of the board.
When a contributor leaves the employ of a municipality which has joined the system, and enters into the employ of another municipality which has also joined the system, his service credits shall remain unimpaired, but in such cases the unpaid municipal liability for prior service shall be prorated by the board between the municipalities on an equitable basis. Such basis will be determined, with the advice of the actuary, according to the number of years of service performed by the contributor for each municipality.
A contributor who has been employed by a municipality for a period of at least six months and is an active member of the system and who thereafter, heretofore, or hereafter, shall be inducted into the military service of the United States in times of war, armed conflict, or National emergency, so proclaimed by the President of the United States, shall have credited to his employment record, for pension or retirement benefits, all of the time spent by him in such military service during the continuance of such war, armed conflict, or National emergency if such person returns or has heretofore returned to his employment within six months after his separation from the service. The municipality shall, during the period of the member's intervening military service, continue to make current service contributions toward the municipal annuity of the member. An active member may file an application with the board for permission to purchase credit toward his member's share of the annuity for intervening military service. These contributions shall be computed by applying the member's contribution rate to his annual rate of compensation at the time of entry of the member into active military service, and multiplying the result by the number of years and fractional part of year of creditable intervening military service, together with interest from date of return to employment to date of purchase. The amount due from the member shall be certified by the board in accordance with methods approved by the actuary, and may be paid by (1) regular monthly payments during active military service, or (2) a lump sum payment within thirty days or (3) it any be amortized with additional interest through salary deductions in amounts agreed upon by the member of the board.
An active member may also purchase credit for other than intervening military service performed for the United States in times of war, armed conflict or National emergency, so proclaimed by the President of the United States, for a period not to exceed five years: Provided, That the member has completed five years of service to the municipality subsequent to such military service. An active member may file an application with the board for permission to purchase credit for nonintervening military service upon completion of five years of subsequent service to the municipality. The type of service credit for such service shall be determined by the date of entry of the municipality into the system. If the date of the member's separation from military service is prior to the date on which the municipality joined the system, then the credit purchased shall be considered as prior service credit. In this case the amount due from the member shall be computed by applying the member's basic contribution rate plus the rate of contribution the municipality paid for current service during its first year of entry into the system to his prior salary and multiplying the result by the number of years and fractional part of a year of creditable nonintervening military service, plus interest from the date of the member's employment by the municipality to the date of purchase. If, on the other hand, the date of the member's separation from military service is later than the date of entry of the municipality into the system, then the credit purchased shall be considered as current service credit. In this case the amount due from the member shall be computed by applying the member's basic contribution rate plus the municipality's normal contribution rate for current service which was in effect on the date of the member's entry into employment with the municipality to his average annual rate of compensation over the first five years of his subsequent employment and multiplying the result by the number of years and fractional part of a year of creditable nonintervening military service being purchased, plus interest from the date of employment by the municipality to date of purchase.
The amount due from the member shall be certified by the board in accordance with methods approved by the actuary, and may be paid in a lump sum within thirty days or it may be amortized with additional interest through salary deductions in amounts agreed upon by the member and the board.
The rate of interest to be charged to members on their purchase of credit for intervening or nonintervening military service shall be the rate being credited by the system to member's contribution accounts in effect on the date of the member's application, compounded annually.
A member may purchase credit for intervening or nonintervening military service only if his discharge or separation from the service was granted under other than dishonorable conditions.
A member may not purchase credit for any military service for which he is entitled to receive, eligible to receive now or in the future, or is receiving retirement benefits for such service under a retirement system administered and wholly or partially paid for by any other governmental agency, or private employer.
Applications for permission to purchase credit for military service must be accompanied by proof of the nature of his discharge or separation from the military service.
53 P.S. § 881.204